In a commonly used type of electric meter, the meter housing is retained on the base plate by a clamping ring of U-shaped cross section which encloses the adjacent flanges of the base and meter housing. The ends of the clamping ring are turned radially outwardly and threaded means is provided for drawing the ends together to tighten the ring around the meter and base flanges.
Various means have been provided for preventing unauthorized persons from loosening the ring to remove the meter to short across the terminals to bypass the meter.
For example, in U.S. Pat. No. 3,867,822 issued Feb. 25, 1975 to Morse et al, there is illustrated a protective housing for a clamping ring, which has apertures positioned to be aligned with apertures in the ends of the clamping ring to receive a locking cylinder. However, when assembled, the head of the locking member is exposed and can be attacked with various tools, such as vise-grip type pliers to provide sufficient tension thereto to fracture the locking mechanism. Another disadvantage of housings of this type is the fact that being a casting, they are brittle and readily broken, and the internal surfaces that provide a locking seat for the locking balls of the locking member vary sufficiently in dimensions to provide erratic locking action, which is often inadequate.